The present invention relates to pipe conduits in general, and more particularly to a method of salvaging or restoring to use a pipe conduit which has suffered damage.
There are already known various methods of salvaging a pipe conduit which is buried under ground, especially of a sewage or waste water channel. Generally speaking, such methods include the use of a lining hose which frequently includes an impermeable layer and an adjacent resin-absorbing layer. This resin-absorbing layer is soaked or permeated with a resin prior to the introduction of the thus treated lining hose into the pipe conduit. After being properly positioned in the pipe conduit, the lining hose is pressed against the inner surface of the pipe conduit by a calibrating hose which is introduced into the interior of the lining hose, and the resin is caused to harden.
Methods of this kind are known for instance, from the German patent DE-PS No. 22 40 153 and DE-PS No. 23 62 784. In these methods, the hardening of the resin is accomplished by the application of heat. To this end, water is fed into the pipe conduit to be salvaged at a temperature of about 80.degree. C. Depending on the particulars of the method used for introducing the calibrating hose into the lining hose, the warm or hot water is being supplied either during or after the introduction of the calibrating hose. Inasmuch as the hardening usually takes place over an extended time period, such as about 24 hours, the water used for hardening the resin must be maintained at the relatively high temperature needed for the hardening of the resin. As a consequence of the substantial amount of the warm or hot water required during the relatively long curing period for achieving the hardening or curing of the resin, there is required a commensurately high consumption of energy, with correspondingly high costs. Moreover, since the hardening or curing takes place, as already mentioned above, over the period of, for instance, 24 hours, it is necessary to provide for the supervision of the hardening or curing operation in the course of this curing time period, as a result of which the costs are further increased.